import java.util.*;

public class Collections_Class {

public static void main(String[] args){

String[] colors={"黑桃","紅桃","梅花","方塊"};

String[] numbers={"A","2","3","4","5","6","7","8","9","10","J","Q","K"};

ArrayList cards = new ArrayList();

int i,j;

for(i=0;i<4;i++){

for(j=0;j<12;j++){

cards.add(colors[i]+numbers[j]);

System.out.print(cards.get(i*12+i+j)+",");

}

cards.add(colors[i]+numbers[j]);

System.out.println(cards.get(i*12+i+j));

}

Collections.sort(cards);//升序

for(i=0;i<4;i++){

for(j=0;j<12;j++){

System.out.print(cards.get(i*12+i+j)+",");

}

System.out.println(cards.get(i*12+i+j));

}

升序的輸出結果：

方塊10,方塊2,方塊3,方塊4,方塊5,方塊6,方塊7,方塊8,方塊9,方塊A,方塊J,方塊K,方塊Q

梅花10,梅花2,梅花3,梅花4,梅花5,梅花6,梅花7,梅花8,梅花9,梅花A,梅花J,梅花K,梅花Q

紅桃10,紅桃2,紅桃3,紅桃4,紅桃5,紅桃6,紅桃7,紅桃8,紅桃9,紅桃A,紅桃J,紅桃K,紅桃Q

黑桃10,黑桃2,黑桃3,黑桃4,黑桃5,黑桃6,黑桃7,黑桃8,黑桃9,黑桃A,黑桃J,黑桃K,黑桃Q

我想知道它是怎么升序的，按什么樣的規則來排序？？？？？？？？？？？？？？